The invention generally relates to providing security, and discloses possibilities for the formation of a security association among devices of a group such as a user group formed by non-expert users.
The two-party case of this problem of forming a secure connection has been studied extensively, and is sometimes referred to as the “First Connect” problem.
The present invention relates to a multi-party case with two or more participants which are able to communicate with each other using wireless communication such as short-range radio communication. The invention further relates to security in networks or groups such as close proximity networks or closed-user-groups, CUG, or in ad-hoc networks, such as Local Area Networks, LANs, or WLANs, Wireless LANs.
A problem may arise when several people are for instance in a meeting room or other environment and want to establish a secure communication session, preferably wireless session, among their personal devices such as laptops, computers, or mobile communication devices such as mobile phones. When there is no prior context (like certificates issued by a common central authority, CA), or no experienced security administrator at hand to help, a problem is to find a user-friendly means of establishing a common security association, SA, that can be used to protect the communication among the devices. A security association consists of the cryptographic keys and other information needed to cryptographically protect communication.
Similar scenarios may also arise in multiplayer games, personal network of multiple devices etc.
Authenticating a multi-party Diffie-Hellman key agreement using a shared short password is known, see Asokan and Ginzboorg, “Key agreement in ad hoc networks”, Computer Communications, April 2000, for reference.
Authenticating two-party Diffie-Hellman using non-secret checksums is also known, see Serge Vaudenay, “Secure Communications over Insecure Channels Based on Short Authenticated Strings”, Advances in Cryptology—CRYPTO 2005, Lecture Notes in Computer Science, LNCS vol. 3621, Springer-Verlag, pp. 309-326, 2005”.
A U.S. Patent Application filed in U.S. Mar. 10, 2005, title “System, Method And Computer Program Product For Authenticating A Data Agreement Between Network Entities”, also discloses a manner of authenticating a data agreement between network entities.
The disclosure contents of this US Patent Application, as well as of the above mentioned articles of Asokan and Ginzboorg, “Key agreement in ad hoc networks”, Computer Communications, April 2000, and Serge Vaudenay, “Secure Communications over Insecure Channels Based on Short Authenticated Strings”, Springer-Verlag, pp. 309-326, 2005, is herewith incorporated into the present application to full extent.